G4M1 also has the 800kg AP bomb as an option.
Ah yes, forgot about that one.
But I think it will see much less usage than the old 800kg GP bomb, which was working very well on towns. The only target justifying the 800kg AP would be the CV, but even if you would hit with all 3 bombs, it would still not be sufficient to sink an undamaged carrier.
Lancs, Ju 88s and so on still way more "efficient", even more so if you consider the tendency of the Betty to flame up just by being aimed at